Optoelectronic modules can be integrated into a wide range of small electronic devices, such as surveillance cameras, camcorders, laptop computers, tablet computers, bio devices, and mobile robots, among others. Such modules may include, for example, an image sensor to capture images. Light entering through an aperture at one end of the module can be directed to the image sensor by an optical system such as one or more passive optical elements (e.g., lenses) disposed in a lens barrel.
In some cases, the lens barrel is mounted by adhesive to a cover glass that is disposed over the image sensor. Such configurations, however, can suffer mechanical problems during thermal cycling. For example, at elevated temperatures, the lens barrel may expand significantly compared to the cover glass. Consequently, the lens barrel may experience significant thermal stresses and, in some instances, the optical elements disposed within the lens barrel may experience significant thermal stresses. During thermal cycling, the thermal stresses can cause mechanical failure in the optoelectronic module such as delamination or cracking of the adhesive or of a component within the optoelectronic module.